Walrus radio-tracking in the Chukchi Sea 2012

USGS Researchers attached satellite radio-tags on 40 Pacific walruses in the
eastern Chukchi Sea in mid-July. Tracking data from this study are intended
to help describe walrus movements, foraging areas, and sea ice habitats
in the Chukchi Sea and the Chukchi Sea oil lease sale planning area and to
provide insights on walrus foraging and movements during ice minimum
conditions in summer.

The top map portrays the track of walruses tracked in 2012.

The bottom map animates through daily locations of tagged walruses and
sea ice distributions. Radio deployment locations are shown with a red X on
the day they occur, while daily walrus relocations are show with a yellow
dot. Sea ice distribution is based on near-real time passive microwave
imagery collected by the Special Sensor Microwave Imager/Sounder (SSMI)
data provided through the National Snow and Ice Data Center (http://nsidc.org/data/docs/daac/nsidc0081_ssmi_nrt_seaice.gd.html) which
provides a daily record of higher ice concentrations (15-100%) on a 25 km
gird; and based on the National Ice Center (NIC) daily marginal ice zone
product, which is based on multiple sensors and active ice analysis (http://www.natice.noaa.gov/products/).